Of Aniline And Its Acetylene Replace The Theoretical Study Of The Electronic Spectra

Aryl tertiary amine compounds are though of the preferred hole-transporting materials, because of their high rate of electron mobility. Furthermore, theirs strong absorption and blue emission in UV-Visible region also satisfy the blue electroluminescent requirements. Specially, triphenylamine derivatives not only are important organic dyes, but also have strong fluorescence properties and optical stability. And they are a very suitable as a material with transport layer for charge carrier, they can create the amine cation radicals and have a good hole transporting properties under the electric field. They also can be used as Electroluminescence hole transport materials. Most hole transporting materials in electroluminescent devices contain the tertiary amine compounds, some small organic molecules and polymers containing tertiary amine as a blue electroluminescent materials are often reported.Triphenylamine derivatives have numerous above-mentioned advantages, in addition, the structures of these compounds could be adjusted easily by introducing of the vinyl, phenyl and other unsaturated groups and various chromophores. These substituted groups will conjugate with the triphenylamine, thereby improve the optoelectronic properties of these compounds. At present, all the research on triphenylamine derivatives are focusing on the molecular structure and the corresponding characteristics, but there is a lack of theoretical calculations for the fluorescence emission spectra and absorption spectra of triphenylamine derivatives, especially the fluorescence spectra and absorption spectra of the ethynyl substituted derivatives.All the calculations are performed with the GAUSSIAN 03 package. Firstly, all molecular geometries are fully optimized at HF/6-31G level, so we got the molecular ground state (So) stable equilibrium configurations. Then, the geometries of the first excited singlet state (Si) are fully optimized at CIS/6-31G* levels. At last, the time-dependent density functional theory at B3LYP/6-31G* level are used to calculate adiabatic transition energy, and the absorption and fluorescence emission spectra are discussed.This dissertation is divided into four chapters: In chapter 1, we introduce the background and current research situation. Experimental data are the base for the research on the molecular excited states and transition spectra. The time-dependent density functional theory affords an effective approach to handle electronic system interaction and excited states.In chapter 2, we describes the luminescence mechanism of organic compounds, and classify the organic light-emitting materials according to their structures, It allows us to get more profound understanding of the luminescence of organic compounds and advise the research on the organic light-emitting materials.In chapter 3, the theoretical methods used in dissertation are introduced, including the principles of the time-dependent density functional theory and configuration interaction method. At same time, we also introduce the development of the quantum chemistry.In chapter 4, the time-dependent density functional theory (TDDFT) is used to calculate the adiabatic transition energy of system, then the absorption and fluorescence emission spectra are also calculated. The results show that the absorption spectroscopy of system are all red shifted because of the affection of ethynyl group. The maximum absorption wavelength of triphenylamine that we calculated is 2.0nm smaller than experimental values. The result of the calculation is quite credible. The calculated fluorescence emission spectrum are also red shifted when the ethynyl group increases, the increasing rate becomes slow with the inceasing ethynyl group. In brief, the substitution ethynyl group will red shift the fluorescence emission spectra of aniline derivatives.In this dissertation, the absorption and fluorescence emission spectra of aniline derivatives are investigated by the quantum chemistry method. The fluorescence emission of aniline derivatives spectra are red shifted with the substitution ethynyl group according to the theoretical calculation. This will help us to find new luminescent materials. We believe that the ethynyl substituted triphenylamine could be the light-emitting materials and their fluorescence emission spectra are in the visible region.